io_interface_mux.c

linux内核源码

/* IO interface mux allocator for ETRAX100LX.
 * Copyright 2004, Axis Communications AB
 * $Id: io_interface_mux.c,v 1.2 2004/12/21 12:08:38 starvik Exp $
 */


/* C.f. ETRAX100LX Designer's Reference 20.9 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/init.h>

#include <asm/arch/svinto.h>
#include <asm/io.h>
#include <asm/arch/io_interface_mux.h>


#define DBG(s)

/* Macro to access ETRAX 100 registers */
#define SETS(var, reg, field, val) var = (var & ~IO_MASK_(reg##_, field##_)) | \
					  IO_STATE_(reg##_, field##_, _##val)

enum io_if_group {
	group_a = (1<<0),
	group_b = (1<<1),
	group_c = (1<<2),
	group_d = (1<<3),
	group_e = (1<<4),
	group_f = (1<<5)
};

struct watcher
{
	void (*notify)(const unsigned int gpio_in_available,
		       const unsigned int gpio_out_available,
		       const unsigned char pa_available,
		       const unsigned char pb_available);
	struct watcher *next;
};


struct if_group
{
	enum io_if_group        group;
	unsigned char           used;
	enum cris_io_interface  owner;
};


struct interface
{
	enum cris_io_interface   ioif;
	unsigned char            groups;
	unsigned char            used;
	char                    *owner;
	unsigned int             gpio_g_in;
	unsigned int             gpio_g_out;
	unsigned char            gpio_b;
};

static struct if_group if_groups[6] = {
	{
		.group = group_a,
		.used = 0,
	},
	{
		.group = group_b,
		.used = 0,
	},
	{
		.group = group_c,
		.used = 0,
	},
	{
		.group = group_d,
		.used = 0,
	},
	{
		.group = group_e,
		.used = 0,
	},
	{
		.group = group_f,
		.used = 0,
	}
};

/* The order in the array must match the order of enum
 * cris_io_interface in io_interface_mux.h */
static struct interface interfaces[] = {
	/* Begin Non-multiplexed interfaces */
	{
		.ioif = if_eth,
		.groups = 0,
		.gpio_g_in = 0,
		.gpio_g_out = 0,
		.gpio_b = 0
	},
	{
		.ioif = if_serial_0,
		.groups = 0,
		.gpio_g_in = 0,
		.gpio_g_out = 0,
		.gpio_b = 0
	},
	/* End Non-multiplexed interfaces */
	{
		.ioif = if_serial_1,
		.groups = group_e,
		.gpio_g_in =  0x00000000,
		.gpio_g_out = 0x00000000,
		.gpio_b = 0x00
	},
	{
		.ioif = if_serial_2,
		.groups = group_b,
		.gpio_g_in =  0x000000c0,
		.gpio_g_out = 0x000000c0,
		.gpio_b = 0x00
	},
	{
		.ioif = if_serial_3,
		.groups = group_c,
		.gpio_g_in =  0xc0000000,
		.gpio_g_out = 0xc0000000,
		.gpio_b = 0x00
	},
	{
		.ioif = if_sync_serial_1,
		.groups = group_e | group_f, /* if_sync_serial_1 and if_sync_serial_3
					       can be used simultaneously */
		.gpio_g_in =  0x00000000,
		.gpio_g_out = 0x00000000,
		.gpio_b = 0x10
	},
	{
		.ioif = if_sync_serial_3,
		.groups = group_c | group_f,
		.gpio_g_in =  0xc0000000,
		.gpio_g_out = 0xc0000000,
		.gpio_b = 0x80
	},
	{
		.ioif = if_shared_ram,
		.groups = group_a,
		.gpio_g_in =  0x0000ff3e,
		.gpio_g_out = 0x0000ff38,
		.gpio_b = 0x00
	},
	{
		.ioif = if_shared_ram_w,
		.groups = group_a | group_d,
		.gpio_g_in =  0x00ffff3e,
		.gpio_g_out = 0x00ffff38,
		.gpio_b = 0x00
	},
	{
		.ioif = if_par_0,
		.groups = group_a,
		.gpio_g_in =  0x0000ff3e,
		.gpio_g_out = 0x0000ff3e,
		.gpio_b = 0x00
	},
	{
		.ioif = if_par_1,
		.groups = group_d,
		.gpio_g_in =  0x3eff0000,
		.gpio_g_out = 0x3eff0000,
		.gpio_b = 0x00
	},
	{
		.ioif = if_par_w,
		.groups = group_a | group_d,
		.gpio_g_in =  0x00ffff3e,
		.gpio_g_out = 0x00ffff3e,
		.gpio_b = 0x00
	},
	{
		.ioif = if_scsi8_0,
		.groups = group_a | group_b | group_f, /* if_scsi8_0 and if_scsi8_1
							  can be used simultaneously */
		.gpio_g_in =  0x0000ffff,
		.gpio_g_out = 0x0000ffff,
		.gpio_b = 0x10
	},
	{
		.ioif = if_scsi8_1,
		.groups = group_c | group_d | group_f, /* if_scsi8_0 and if_scsi8_1
							  can be used simultaneously */
		.gpio_g_in =  0xffff0000,
		.gpio_g_out = 0xffff0000,
		.gpio_b = 0x80
	},
	{
		.ioif = if_scsi_w,
		.groups = group_a | group_b | group_d | group_f,
		.gpio_g_in =  0x01ffffff,
		.gpio_g_out = 0x07ffffff,
		.gpio_b = 0x80
	},
	{
		.ioif = if_ata,
		.groups = group_a | group_b | group_c | group_d,
		.gpio_g_in =  0xf9ffffff,
		.gpio_g_out = 0xffffffff,
		.gpio_b = 0x80
	},
	{
		.ioif = if_csp,
		.groups = group_f, /* if_csp and if_i2c can be used simultaneously */
		.gpio_g_in =  0x00000000,
		.gpio_g_out = 0x00000000,
		.gpio_b = 0xfc
	},
	{
		.ioif = if_i2c,
		.groups = group_f, /* if_csp and if_i2c can be used simultaneously */
		.gpio_g_in =  0x00000000,
		.gpio_g_out = 0x00000000,
		.gpio_b = 0x03
	},
	{
		.ioif = if_usb_1,
		.groups = group_e | group_f,
		.gpio_g_in =  0x00000000,
		.gpio_g_out = 0x00000000,
		.gpio_b = 0x2c
	},
	{
		.ioif = if_usb_2,
		.groups = group_d,
		.gpio_g_in =  0x0e000000,
		.gpio_g_out = 0x3c000000,
		.gpio_b = 0x00
	},
	/* GPIO pins */
	{
		.ioif = if_gpio_grp_a,
		.groups = group_a,
		.gpio_g_in =  0x0000ff3f,
		.gpio_g_out = 0x0000ff3f,
		.gpio_b = 0x00
	},
	{
		.ioif = if_gpio_grp_b,
		.groups = group_b,
		.gpio_g_in =  0x000000c0,
		.gpio_g_out = 0x000000c0,
		.gpio_b = 0x00
	},
	{
		.ioif = if_gpio_grp_c,
		.groups = group_c,
		.gpio_g_in =  0xc0000000,
		.gpio_g_out = 0xc0000000,
		.gpio_b = 0x00
	},
	{
		.ioif = if_gpio_grp_d,
		.groups = group_d,
		.gpio_g_in =  0x3fff0000,
		.gpio_g_out = 0x3fff0000,
		.gpio_b = 0x00
	},
	{
		.ioif = if_gpio_grp_e,
		.groups = group_e,
		.gpio_g_in =  0x00000000,
		.gpio_g_out = 0x00000000,
		.gpio_b = 0x00
	},
	{
		.ioif = if_gpio_grp_f,
		.groups = group_f,
		.gpio_g_in =  0x00000000,
		.gpio_g_out = 0x00000000,
		.gpio_b = 0xff
	}
	/* Array end */
};

static struct watcher *watchers = NULL;

static unsigned int gpio_in_pins =  0xffffffff;
static unsigned int gpio_out_pins = 0xffffffff;
static unsigned char gpio_pb_pins = 0xff;
static unsigned char gpio_pa_pins = 0xff;

static enum cris_io_interface gpio_pa_owners[8];
static enum cris_io_interface gpio_pb_owners[8];
static enum cris_io_interface gpio_pg_owners[32];

static int cris_io_interface_init(void);

static unsigned char clear_group_from_set(const unsigned char groups, struct if_group *group)
{
	return (groups & ~group->group);
}


static struct if_group *get_group(const unsigned char groups)
{
	int i;
	for (i = 0; i < ARRAY_SIZE(if_groups); i++) {
		if (groups & if_groups[i].group) {
			return &if_groups[i];
		}
	}
	return NULL;
}


static void notify_watchers(void)
{
	struct watcher *w = watchers;

	DBG(printk("io_interface_mux: notifying watchers\n"));

	while (NULL != w) {
		w->notify((const unsigned int)gpio_in_pins,
			  (const unsigned int)gpio_out_pins,
			  (const unsigned char)gpio_pa_pins,
			  (const unsigned char)gpio_pb_pins);
		w = w->next;
	}
}


int cris_request_io_interface(enum cris_io_interface ioif, const char *device_id)
{
	int set_gen_config = 0;
	int set_gen_config_ii = 0;
	unsigned long int gens;
	unsigned long int gens_ii;
	struct if_group *grp;
	unsigned char group_set;
	unsigned long flags;

	(void)cris_io_interface_init();

	DBG(printk("cris_request_io_interface(%d, \"%s\")\n", ioif, device_id));

	if ((ioif >= if_max_interfaces) || (ioif < 0)) {
		printk(KERN_CRIT "cris_request_io_interface: Bad interface %u submitted for %s\n",
		       ioif,
		       device_id);
		return -EINVAL;
	}

	local_irq_save(flags);

	if (interfaces[ioif].used) {
		local_irq_restore(flags);
		printk(KERN_CRIT "cris_io_interface: Cannot allocate interface for %s, in use by %s\n",
		       device_id,
		       interfaces[ioif].owner);
		return -EBUSY;
	}

	/* Check that all required groups are free before allocating, */
	group_set = interfaces[ioif].groups;
	while (NULL != (grp = get_group(group_set))) {
		if (grp->used) {
			if (grp->group == group_f) {
				if ((if_sync_serial_1 ==  ioif) ||
				    (if_sync_serial_3 ==  ioif)) {
					if ((grp->owner != if_sync_serial_1) &&
					    (grp->owner != if_sync_serial_3)) {
						local_irq_restore(flags);
						return -EBUSY;
					}
				} else if ((if_scsi8_0 == ioif) ||
					   (if_scsi8_1 == ioif)) {
					if ((grp->owner != if_scsi8_0) &&
					    (grp->owner != if_scsi8_1)) {
						local_irq_restore(flags);
						return -EBUSY;
					}
				}
			} else {
				local_irq_restore(flags);
				return -EBUSY;
			}
		}
		group_set = clear_group_from_set(group_set, grp);
	}

	/* Are the required GPIO pins available too? */
	if (((interfaces[ioif].gpio_g_in & gpio_in_pins) != interfaces[ioif].gpio_g_in) ||
	    ((interfaces[ioif].gpio_g_out & gpio_out_pins) != interfaces[ioif].gpio_g_out) ||
	    ((interfaces[ioif].gpio_b & gpio_pb_pins) != interfaces[ioif].gpio_b)) {
		local_irq_restore(flags);
		printk(KERN_CRIT "cris_request_io_interface: Could not get required pins for interface %u\n",
		       ioif);
		return -EBUSY;
	}

	/* All needed I/O pins and pin groups are free, allocate. */
	group_set = interfaces[ioif].groups;
	while (NULL != (grp = get_group(group_set))) {
		grp->used = 1;
		grp->owner = ioif;
		group_set = clear_group_from_set(group_set, grp);
	}

	gens = genconfig_shadow;
	gens_ii = gen_config_ii_shadow;

	set_gen_config = 1;
	switch (ioif)
	{
	/* Begin Non-multiplexed interfaces */
	case if_eth:
		/* fall through */
	case if_serial_0:
		set_gen_config = 0;
		break;
	/* End Non-multiplexed interfaces */
	case if_serial_1:
		set_gen_config_ii = 1;
		SETS(gens_ii, R_GEN_CONFIG_II, sermode1, async);
		break;
	case if_serial_2:
		SETS(gens, R_GEN_CONFIG, ser2, select);
		break;
	case if_serial_3:
		SETS(gens, R_GEN_CONFIG, ser3, select);
		set_gen_config_ii = 1;
		SETS(gens_ii, R_GEN_CONFIG_II, sermode3, async);
		break;
	case if_sync_serial_1:
		set_gen_config_ii = 1;
		SETS(gens_ii, R_GEN_CONFIG_II, sermode1, sync);
		break;
	case if_sync_serial_3:
		SETS(gens, R_GEN_CONFIG, ser3, select);
		set_gen_config_ii = 1;
		SETS(gens_ii, R_GEN_CONFIG_II, sermode3, sync);